Cisco 400-007 Exam With Confidence Using Practice Dumps

Dense Wavelength Division Multiplexing (DWDM) enables multiple optical signals to be transmitted simultaneously on different wavelengths over a single fiber, allowing:

B: Efficient bandwidth expansion without laying new fiber infrastructure.

C: Topology flexibility and service protection using built-in features like optical protection switching, automatic fault detection, and self-healing rings.

Why other options are incorrect:

A: Oversubscription of bandwidth applies more to packet-based networks, not DWDM optical layer.

D: Chromatic dispersion is managed but not an inherent “intelligent” feature in DWDM.

E: Service protection at the DWDM layer operates independently of upper layer protocols.

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The IoT ecosystem continues to evolve around industry-wide agreements on protocols, frameworks, security, interoperability, and standards:

D: Multiple IoT consortia (such as Industrial Internet Consortium, Open Connectivity Foundation, etc.) are still developing open frameworks and interoperability models.

E: IoT standards for security, data privacy, management, and protocol interoperability are still maturing as the market rapidly evolves.

Why other options are incorrect:

A: Wi-Fi protocols (such as 802.11ax) are already mature and standardized for IoT.

B: Regulatory domains (frequency allocations, power levels) are already well-established.

C: Low-energy Bluetooth sensors are already standardized and widely implemented.

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D: CWDM (Coarse Wavelength Division Multiplexing) shares parts of the same optical transmission window (1260–1625 nm) as DWDM but uses wider spacing between channels (typically 20 nm apart).

E: CWDM typically uses passive devices (multiplexers and demultiplexers) that require no electrical power, making deployment cost-effective.

Incorrect Options:

A: CWDM is better suited for shorter distances (up to ~80 km) and doesn't typically use optical amplifiers (EDFA). DWDM is better for long-haul with amplification.

B: 850 nm is used in multimode fiber systems (not CWDM).

C: CWDM supports up to 18 channels; DWDM supports up to 32 or more.

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